Li Yong 李顒 (1627-1705), courtesy name Zhongfu 中孚, style Erqu 二曲, Erqu xiansheng 二曲先生 or Canfu 慚夫, was a Confucian scholar of the early Qing period 清 (1644-1911). Together with Huang Zongxi 黃宗羲 (1610-1695) and Sun Qifeng 孫奇逢 (1585-1675), Li Yong was called one of the three great Confucians of the early Qing period (Qingchu san da ru 清初三大儒).

He hailed from Zhengwu 整屋 (modern Zhouzhi 周至, Shaanxi) and grew up in a poor family. Yet with the support of the owner of a library he was able to obtain the necessary education to study the Confucian Classics, books on history, the various masters and philosophers, and Buddhist writings. With the age of 30 he became a visiting lecturer at the Guanzhong Academy 關中書院 and learned himself a lot from professional teachers. Luo Zhonglin 駱仲麟, prefect (zhifu 知府) of Changzhou 常州, invited him to teach in his town. The presence of Li Yong attracted quite a few students from the surrounding prefectures of Wuxi 無錫, Jiangyin 江陰 and Yihi 宜興.

The Qing court was highly interested in Li Yong's influence on the local elite in the lower Yangtze region and therefore several times invited him to take over a government post in the educational system, but Li Yong stubbornly refused. In 1685 the Kangxi Emperor 康熙 (r. 1662-1722) himself, on his southern inspection tour, repeated the invitation, but Li Yong never became an official of the Qing dynasty. His understanding of being a free teacher wholly contradicted the concept of the Qing rulers who liked to integrate as much social groups as possible into the administrative structure of the empire.

Li Yong was an eclecticist. He had not obtained a proper education and therefore chose these teachings that he regarded as the most useful. His philosophy therefore shows traces of both the Song period 宋 (960-1279) Neo-Confucian Zhu Xi 朱熹 (1130-1200) as well as of the Ming period 明 (1368-1644) philosopher Wang Shouren 王守仁 (Wang Yangming 王陽明), who stood in the tradition of Lu Jiuyuan 陸九淵 (1139-1193), who in many respects had been an opponent of Zhu Xi.

According to Li Yong, man had to repent his faults and to renew his life and thoughts. He has to put his energies into practicing propriety and humility, in order to "save the world and support the time" (jiu shi ji shi 救世濟時). For him, the practice of the Confucian philosophy was more important than theoretical concepts. He therefore stressed that it is important to "illuminate its embodiment and o adapt its usefulness" (ming ti shi yong 明體適用). The theory of "virtues" (de 德) has to be transformed into practical efforts (gong 功). While the theory is important for the cultivation of the self, the practice of virtue is important to benefit society.

Li Yong enumerated those masters whose teachings could be useful for the intellectual and the practical way of performing virtue, namely Yan Hui 顏回 (521-481 BCE), Zeng Shen 曾參 (505-436), Zisi 子思 (483-402 BCE), Mengzi 孟子 (385-304 or 372-289 BCE), Zhou Dunyi 周敦頤 (1017-1073), Cheng Hao 程顥 (1032-1085), Zhang Zai 張載 (1020-1077) and Zhu Xi for the inner cultivation, and Yi Yin 伊尹, Fu Yue 傅說, the Duke of Zhou 周公, the Duke of Shao 召公奭, Zhuge Liang 諸葛亮 (181-234), Wang Yangming for social practise. Li Yong said that the foundation of everything is to illuminate the Way that is embedded in one's heart. Only then it is possible to command virtues to function in a society.

In Li Yong's view, the Confucian attempt to "study things thoroughly in order to achieve knowledge" (ge wu zhi zhi 格物致知) even included practical matters like rituals, music, military affairs, penal law, taxes and labour services, agriculture and settlement, and even the book Taixi shuifa 泰西水法 "Hydraulic Methods of the Great West", written by the Jesuit missionary Sabatino De Ursis (1575-1620, Chinese name Xiong Sanba 熊三拔) and translated into Chinese by Xu Guangqi 徐光啟 (1562-1633).

After a discussion on the practical use of Confucian virtues, the philosopher Gu Yanwu 顧炎武 (1613-1682) praised Li Yong for his achievements that he had reached by bitter self-instruction and wholly without tutorial guidance. Li Yong transmitted the teachings of Lu Jiuyuan and Wang Yangming without the intention to enrich them with his own interpretations or thaughts. Instead, he saw himself as a teacher, much like the model of the Master Confucius himself. In his later years Li Yong even destroyed all his earlier writings and ceased to note down his thoughts.

For this reason, not much of his writings has survived. The extant texts are assembled in the collection Erquji 二曲集 and the treatise Sishu fanshen lu 四書反身錄.